Absorbable vascular filter

Abstract

An absorbable vascular filter is disclosed for deployment within a vessel for temporary filtering of body fluids. A preferred embodiment is the placement of such absorbable vascular filter within the inferior vena cava (IVC) to filter emboli for the prevention of pulmonary embolism for a limited duration in time. Once protection from PE is complete, the filter is sequentially biodegraded according to a planned schedule determined by the absorption properties of the filter components. Hence the temporary absorbable vascular filter obviates the long term complications of permanent IVC filters such as increased deep vein thrombosis, while also circumventing the removal requirement of metal retrievable IVC filters.

What is claimed is: 
     
       1. An absorbable filter configured for intra vena cava deployment comprising:
 a rigid polymeric circumferential element for attaching the filter to a vessel, the circumferential element configured to provide sufficient radial force to maintain placement in the vessel; and 
 a plurality of absorbable capture elements affixed to the rigid polymeric circumferential element for capturing unwanted substances flowing in a vessel for a limited period of time, 
 wherein the circumferential element is characterized by a first lattice spacing and the plurality of absorbable capture elements are characterized by a second lattice spacing, the first lattice spacing formed by a sinusoidal circumferential element lattice, the second lattice spacing formed by a cross-sectional petal structure of the filter formed by the plurality of absorbable capture elements transverse to a longitudinal axis of the filter, 
 wherein individual ones of the plurality of absorbable capture elements are linked with adjacent absorbable capture elements via an absorbable inner capture element coupled with the plurality of absorbable capture elements to establish the second lattice spacing, 
 wherein the linking by the inner capture element creates a first portion of the cross-sectional petal structure between the plurality of absorbable capture elements having a plurality of first petals with a first petal spacing, and a second portion of the cross-sectional petal structure between the plurality of absorbable capture elements having a plurality of second petals with a second petal spacing, the plurality of absorbable capture elements extending from apexes of the sinusoidal circumferential element lattice toward the absorbable inner capture element, the plurality of absorbable capture elements configured such that the first portion of the cross-sectional petal structure and the second portion of the cross-sectional petal structure are located in a lumen of the vena cava to capture or retard the substances flowing in the vessel; and 
 wherein the circumferential element, the plurality of absorbable capture elements, and the absorbable inner capture element are fully resorbable such that after a target prophylactic time window for filter utilization, these components are biologically absorbed, resulting in an absence of these filter components in the vessel, wherein the first and second portions of the cross-sectional petal structure do not extend past the inner capture element toward a radial center of the circumferential element, and the plurality of first and second petals loop through the inner capture element to integrate the first and second portions of the cross-sectional petal structure to form a capture basket. 
 
     
     
       2. A device as set forth in  claim 1 , wherein ends of the absorbable capture elements are attached to the apexes of the sinusoidal circumferential element lattice to form the first and second portions of the cross-sectional petal structure, such that collectively the first and second portions of the cross-sectional petal structure form a capture basket. 
     
     
       3. A device as set forth in  claim 1 , wherein a subset of the absorbable capture elements are chosen to sequentially degrade in time to avoid simultaneous bulk release of capture elements in the vessel over time. 
     
     
       4. A device as set forth in  claim 1 , wherein the plurality of absorbable capture elements are fabricated from absorbable materials chosen from a group including polydioxanone, polytrimethylene carbonate, polyglactin, polyglycolic acid, poliglecaprone, polyglytone, and polylacticoglycolic acid. 
     
     
       5. A device as set forth in  claim 1 , wherein the plurality of absorbable capture elements are absorbable sutures. 
     
     
       6. A device as set forth in  claim 5 , wherein the plurality of absorbable capture elements are constructed from absorbable sutures chosen from a group including Vicryl, Monocryl, PDS, PDS II, Dexon, Dexon II, Maxon, PLGA, Surgical Gut, Ethibond, Panacryl, and Caprosyn. 
     
     
       7. A device as set forth in  claim 1 , wherein the circumferential element is fabricated of absorbable materials chosen from a group including polydioxanone, polytrimethylene carbonate, polyglactin, polyglycolic acid, poliglecaprone, polyglytone, and polylacticoglycolic acid. 
     
     
       8. A device as set forth in  claim 1 , wherein the circumferential element comprises an anchor element or barb for attachment to a vessel. 
     
     
       9. An absorbable filter comprising:
 a circumferential element attached to a vessel; and 
 a capture basket affixed to the circumferential element for capturing unwanted substances flowing in a vessel for a limited period of time, 
 wherein the circumferential element is characterized by a first lattice spacing and the capture basket is characterized by a second lattice spacing, the first lattice spacing formed by a sinusoidal circumferential element lattice, the second lattice spacing formed by a cross-sectional petal structure of the filter formed by the capture basket transverse to a longitudinal axis of the filter, 
 wherein the capture basket comprises a plurality of absorbable capture elements and an absorbable inner capture element configured to link the plurality of absorbable capture elements to establish the second lattice spacing, 
 wherein linking of the plurality of absorbable capture elements by the inner capture element creates a first portion of the cross-sectional petal structure between the plurality of absorbable capture elements having a plurality of first petals with a first petal spacing, and a second portion of the cross-sectional petal structure between the plurality of absorbable capture elements having a plurality of second petals with a second petal spacing, the plurality of absorbable capture elements extending from apexes of the sinusoidal circumferential element lattice toward the absorbable inner capture element, the plurality of absorbable capture elements configured such that the first portion of the cross-sectional petal structure and the second portion of the cross-sectional petal structure are located in a lumen of the vena cava to capture or retard the substances flowing in the vessel, and 
 wherein the circumferential element, the capture basket including the plurality of capture elements, and the absorbable inner capture element are fully resorbable such that after a target prophylactic time window for filter utilization, these components are biologically absorbed, resulting in an absence of these filter components in the vessel, wherein the first and second portions of the cross-sectional petal structure do not extend past the inner capture element toward a radial center of the circumferential element, and the plurality of first and second petals loop through the inner capture element to integrate the first and second portions of the cross-sectional petal structure to form a capture basket. 
 
     
     
       10. A device as set forth in  claim 9 , wherein the capture basket is a mesh. 
     
     
       11. A device as set forth in  claim 10 , wherein the capture basket is fabricated from materials chosen from a group including polypropylene, polypropylene encapsulated in polydioxanone, polypropylene co-knitted with polyglycolic acid fibers, polyethylene terephathalate, and ePTFE. 
     
     
       12. A device as set forth in  claim 10 , wherein the capture basket is fabricated from materials chosen from a group including polypropylene as in C-QUR™, polypropylene encapsulated by polydioxanone as in PROCEED®, polypropylene co-knitted with polyglycolic acid fibers as in Bard Sepramesh™ IP Composite, polyethylene terephathalate as in Parietiex™ Composite, and ePTFE as in DUALAMESH®. 
     
     
       13. A method for delivering a filter as claimed in  1  or  claim 9  with a delivery catheter, wherein the delivery comprises:
 inserting the filter, in compressed form, within a delivery catheter through the femoral or jugular vein to a desired position within a vessel at or near a vena cava; and 
 deploying the filter in expanded form at the desired position within a vessel; and 
 subsequently removing the delivery catheter from the vessel back through the femoral or jugular vein.